Bolt operating mechanism for machine guns



Feb. 16, 1932. R. c. CO'UPLAND BOLT OPERATING MECHANISM FOR MACHINE GUNSFiled Jan. 9, 1931 mmvrm R. I: Emu land Patented Feb. 16, 1932 UNITESTATES?- BICHABD C.

COUPLAND,-OE THE UNITED STATES ARMY, NORFOLK, VIRGINIA Application filedJanuary 9,

(GRANTED UNDER THE ACTOR MARCH 3,

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without payment to me of anyroyalty thereon.

This invention relates to abolt operating mechanism for machine guns.

Machine guns are provided with a bolt handle to permit manual retractionof the bolt in order to reproduce the action of the gun mechanism duringfiring for the purpose of initially loading the gun and correctingstoppages. When a-vgun is mounted, as in aircraft, so that the bolthandle is inaccessible to the gunner, an operating mechanism isprovided.

The operating mechanism of the present invention is of the typeconsisting of a slide retracted by means of a flexible cable and havingan individual return spring. It is arranged to insure a smooth andpositive functioning, to distribute the shock of arresting the slide,and to facilitate initial retraction of the slide when the gun barrel islocked to the bolt.

With the foregoing and other objects in view, the invention residesinthe novel :11- rangement and combinationof parts and in the details ofconstruction hereinafter described and claimed, it being understood thatchanges in the precise embodiment of the invention herein disclosed maybe made within the scope of what is claimed without departing from thespirit of the invention.

A practical embodiment of the invention is illustrated in theaccompanying drawings, wherein:

Fig. 1 is a view in side elevation of a machine gun equipped with theimproved bolt operating mechanism;

Fig. 2 is an enlarged view, partly in longitudinal section and partly inside elevation of the bolt operating mechanism;

Fig. 3, 4 and 5 are detail sectional the respective lines of Fig. 2; and

Fig. 6 isa view in side elevation and partly in section showing amodified form of operating mechanism. 4

In Fig. 1 the side plate 6 of a machine gun is formed with alongitudinally extending views on The rear 1981. Serial No. 507,614.

1883, AS AMENDED APRIL 30, 1928; 370 0. G. 757) slot 7 in which theoperating handle 8 of the breech bolt reciprocates during actuation ofthe gun. Secured to the side plate at either end of the slot are frontand rear brackets -9 and 10 for supportinga tube 11 parallel to anddirectly below the slot 7.

The front bracket 9 (see Fig. 3) is formed with a' plurality of lugs 12receivable in correspondingly shaped recesses 13 in the side plate 6. Ascrew 14 passing through the bracket and also through the tube isthreaded into the side plate.

The rear bracket 10 consistsof a block 15 having a chambered portion forhousing a pair of spaced rollers 16-16. A cover plate 17 closing thechambered portion and receiving one end of the roller trunnions 16a issecured to the block by means of screws 18. The block is secured to theside plate 6 through screws 19 and a rib 20 on the inside of the blockabuts against the rear edge of the side plate and serves to hold theblock steady.

tudinally extending bore, the forward portion of which isenlargedtoreceive the rear end of the tube 11 and the rear portion receiving ahollow plug 21 attached to a handle 22. A lever 23 constituting a gripmember for the handle is pivotally carried by the handle and has alimited movement with respect thereto by virtue of a pin and slotconnection respectively indicated at 24 and 25.

Mounted on the tube 11 is a tubular slide 26 having a hook 27 engagingthe forward side of the bolt handle 8. A plug 28 within the tube 11 isconnected to the slide by a web 28a projecting through a slot 29 in theupper surface. of the tube. A spring 30 confined between the plug 28 andthe block 15 serves to normally maintain the slide at the forward end ofthe tube. The slide is retracted by means of a flexible cable 31 securedto the plug 28 and to the lever 23 and adapted to be trained over one orthe other of the rollers 16. The upper and lower portions of the rearend of the block are provided with notches 32 behindwhich a bead 33 onthe cable may be engaged. This is for the purpose of retaining the boltin the retracted position.

bracket is pro vided with a longi- The operation of retracting the boltconsists merely in grasping the lever and pulling to the rear. Thepreliminary movement of the lever relative to the handle covers theinitial retraction of the bolt and its separation from the gun barrel.When the handle is released the spring 30 restores the slide to itsforward position so that no additional burden is placed on the returnspring of the bolt. The slide is arrested when it strikes the frontbracket and when the handle strikes the rear bracket.

In the modification shown in Fig. 6 the lever 23 is omitted and thecable 31a is directly attached to the handle 22a which is formed to bereadily gripped. The tube 11 is attached to the block 15a by meansof ahollow plug 34.

I claim:

1. Mechanism for manually operating the bolt of a machine gun includinga front and rear bracket securable to the gun, a tube carried by'thebrackets, a slide carried by the tube and engageable with the bolt ofthe gun, a spring for normally holding the slide at the forward end ofthe tube, a flexible cable attached to the slide, spaced rollerspositioned in the rear bracket to guide the cable, a handle having arigid guide insertable in the rear bracket, and a lever having a limited movement relative to the handle and attached to the cable.

2. Mechanism for manually operating the bolt-of a machine gun includinga support securable to the gun, a slide carried b the support andengageable with the bolt of the gun, a flexible cable attached to theslide, rollers for guiding the cable, a handle having a rigid guideinsertable between the rollers, and a lever having a limited movementrelative to the handle and attached to. the cable.

. 3.- Mechanism for manually operating the bolt of a machine gunincluding a support securable to the gun, a slide carried by the supportand engageable with the bolt of the gun, a flexible cable attached tothe slide, rollers for guiding the cable, a handle having a' rigid guideinsertablein the support and a lever having a limited movement relativeto the handle and attached to the cable. 7

4. Mechanism for'manually operating the bolt of a machine gun includinga support securable to the gun, a slide carried by the support andengageable with the bolt of the gun, a flexiblecable attached to theslide,

a handle having a rigid guide insertable in andmeans for the support,and a lever having a limited movement relative to the handle andattached to the cable.

5. In a gun, an axially movable breech bolt retracting the bolt includjna handle having 'an initial lever action an a subsequent axial movement.

RICHARD C. COUILAND.

